New mooring lines for finger pontoon?

[nigelmercier]

I've got a hotchpotch of mooring lines when I berth at my marina. I've measured the span, and I need 6m for each of four lines, allowing an extra metre.

The berth has two lazy-lines, and I have two long lengths of 3-strand 25mm from the main pontoon to the midships cleats. The four new lines will be rigged as port and starboard to the main pontoon, plus an extra one to the finger pontoon more in the direction of the prevailing wind, midships to near end of finger for low tide when the lazy lines go slack.

I figure that it is best to use 3-strand Nylon, as the boat will be left for long periods; when berthing elsewhere I prefer braided lines. I've tried using Forsheda mooring compensators, they keep snapping. Lines are currently 18mm, but I think I need to check this.

Is this a reasonable setup, and where best to get the cordage?

 

[colind3782]

I replaced my mooring lines with 20mm 3 strand nylon after a particularly strong Tramontana last year and I think that's the biggest I need to go. It's the biggest that will fit the fairleads anyway but it feels pretty bombproof now. Do you need 25mm?

I got the line from UK Yacht Rigging and Supplies Ltd. on ebay. It was the best deal I could find and they were very helpful when I asked questions.

 

[Twister_Ken]

According to Jimmy Green (http://www.jimmygreen.co.uk/p/technical/yacht-ropes-and-rigging-technical-articles-/rope-breaking-strain-guide) 18mm 3ply nylon has a breaking strain of 7 tonnes. Do you really need that much? You could lift my boat with one of those!

 

[nigelmercier]

According to Jimmy Green (http://www.jimmygreen.co.uk/p/technical/yacht-ropes-and-rigging-technical-articles-/rope-breaking-strain-guide) 18mm 3ply nylon has a breaking strain of 7 tonnes. Do you really need that much? You could lift my boat with one of those!

Same site has guide based on boat length, in my case 47'

http://www.jimmygreen.co.uk/p/techn...-technical-articles-/mooring-warps-size-guide

So yes!

 

[cryan]

Am I misreading the OP? Are you saying you will be using eight mooring lines plus an extra storm hawser in bad weather? Are you tying your boat up or knitting it to the pontoon?

I like to put a spliced eye of at least a metre in each rope to make lassoing cleats/bitts/bollards easy so I would compensate for that. If you have experienced parting lines before perhaps try dyneema multiplat? Mainbrace Marine in Rosyth are good guys for rope. I'm sure they could advise you on what best suits your needs.

 

[nigelmercier]

Am I misreading the OP? Are you saying you will be using eight mooring lines plus an extra storm hawser in bad weather?

Two forward pulling on, two lazy-lines aft pulling off, two midships, two alongside pulling off for low tide, plus extra line to windward. Yes, I make that nine. About normal for here, winds of 40kn are quite common.

Some people don't have the extra windward line, some not two alongside. I have to moor quite close as it's a big boat, second biggest on the pontoon, and much longer than the finger.

Lassoing doesn't enter into it, these stay in my berth.

 

[Daydream believer]

3 strand polypropylene 25 diameter
Floats, easy to splice & cheap enough to chuck away every couple of years or if a bit gets chaffed